Transosseous core approach and instrumentation for joint replacement and repair

ABSTRACT

The present invention relates to a method and instrumentation for gaining access to areas in and around joints for treatment and to provide new implants and instrumentation adapted for the new method. In a transosseous core approach of the present invention, the joint is entered through a pathway provided in a portion of a joint bone. Such pathway is preferably made by taking out a bone core from the bone in or adjacent to the joint, wherever possible without substantially compromising physical integrity and physiological viability of the joint. Typically the main route for the transosseous core approach traverses through a more-accessible bone of the joint which can be aligned with a less-accessible bone of the joint in order to facilitate treatment of articular surfaces and/or other structures in the joint. The transosseous pathway into the joint is preferably provided by novel surgical instruments such as a core cutter, cartilage punch, hemostatic device, and retractable axial/transaxial cutting device. Implants modules are also provided which can be inserted into the joint through the transosseous pathway and assembled in situ inside the joint to form an implant assembly.

FIELD OF THE INVENTION

[0001] The present invention relates to instrumentation, implants, andtechniques for orthopedic surgery and, more particularly, to atransosseous core approach for joint repair, replacement, and/ortreatment, wherein the treatment site is approached through atransosseous pathway constructed by taking a bone core out of a bone, atthe joint.

BACKGROUND OF THE INVENTION

[0002] An orthopedic surgeon may wish to gain entry to a particularjoint for multiple reasons. The surgeon may wish to alter or remove adefect in the joint, to replace an articular surface of the joint or theentire joint (i.e., total joint arthroplasty), to transplant cartilageautographs/implants and/or to alter the characteristics of soft tissuesin and around the joint such as tendons, ligaments, joint capsule, etc.In a typical joint, the articular surfaces of the joint are surroundedby soft tissue structures, injury to which is often undesirable or atleast to be minimized. FIG. 1 schematically illustrates a typical joint(representative of diarthroses) and surrounding anatomical structures ofthe joint. The exemplary joint includes first bone “A” and second bone“B”, each including the articular surface 1A, 1B comprising articularcartilage enclosed within a synovial lining 2. Articular surfaces 1A, 1Band synovial lining 2 are in turn surrounded by a joint capsule 3 onwhich a bursa 5 may be disposed. The synovial lining is also referred toas the synovial stratum, which together with the fibrous stratum, makeup the articular capsule. Bones A, and B are attached to tendon 6 andmuscle 7 and are coupled to each other by ligaments 4. Blood vessels andnerves (not shown) generally run with muscle 7, tendon 6, and/orligaments 4. Each bone A, B includes portions of non-articular surface8A, 8B outside joint capsule 3 that are substantially clear of theabove-mentioned soft tissue structures of the joint.

[0003] Conventional methods for gaining access into the joints typicallyrequire wide exposures and joint dislocation. See for example U.S. Pat.No. 4,550,450, entitled “Total Shoulder Prosthesis System,” and U.S.Pat. No. 5,507,833, entitled “Hip Replacement and Method for ImplantingThe Same.” These classical wide exposures damage large area of tissue,create large scars, jeopardize neurovascular structures, produceconsiderable blood loss, increase the potential for other significantcomplications, and increase the risk of infection. Wide exposures,because of their inherent nature, traumatize tissues as they are cut,retracted, and/or divided. The amount of tissue disrupted increases thehealing time and the physiological strain on the patient because theamount and severity of postoperative pain correlate directly to the sizeof the incision and extent of surgery. Traditional wide exposures canalso create limits on the functional results of surgery to treat jointproblems by the sequlae introduced by the exposure itself. More recentdevelopments in arthroscopic techniques may reduce the amount of traumato which a patient may be subjected, but many procedures are notamenable to arthroscopic techniques and frequently such procedures stillentail damage to soft tissue structures surrounding the joint such asthe articular capsule.

[0004] Patient cooperation is an important factor in postoperativerehabilitation. The ultimate result of the treatment of joint problemshinges to a major degree on this fact. Postoperative pain which isproportional to the incision size, exposure, and/or tissue damage,inhibits the rate of patient's rehabilitation. The inability to reachdesired rehabilitation goals often results in an overall inferior and/oran unsatisfactory result. These additional drawbacks of conventionaljoint surgical exposures and treatments contribute to reduce theultimate outcome of the surgical intervention, often introducingunwanted and unnecessary sequlae.

SUMMARY OF THE INVENTION

[0005] In the present invention, a joint is entered via a route passingthrough a pathway provided in a portion of a joint bone. Such pathway ismade by taking out a bone core from the bone in or adjacent to the jointwithout substantially compromising physical integrity and physiologicalviability of the joint. Typically the main route for the presentinvention traverses through a more-accessible bone of the joint whichcan be aligned with a less-accessible bone of the joint to facilitatetreatment of the articular surfaces and/or other structures in thejoint.

[0006] The present invention thus provides a new method andinstrumentation for gaining access to areas in and around the jointsurfaces to treat problems of the joint as well as to provide newimplants and instrumentation adapted for the new method. Thetransosseous core approach of the present invention has at least twomain advantages over conventional surgical exposures. A first is thatthe present invention requires substantially smaller incisions thanstandard exposures. A second is that the present invention does notsubstantially interfere with normal anatomical structures surroundingthe joint such as vascular, nervous, muscular, ligamentous, and othersoft tissues of the joint and, therefore, is less invasive.Additionally, in many cases the exposure obtained by the transosseouscore approach provides better and more direct access to areas of thejoint not found in current exposures.

[0007] Every joint includes at least two bones arranged to allowmovement thereof. Each bone includes an articular surface substantiallyenclosed within a joint capsule and a non-articular surface (e.g., asuperficial portion thereof) disposed substantially outside the jointcapsule. The present invention is based on the transosseous coreapproach where the articular surface of the bone and other tissueswithin the joint capsule can be accessed through a pathway (such as thehole) in the bone commencing from its non-articular surface andapproaching its articular surface.

[0008] Accordingly, in one aspect of the present invention, a method maybe provided to treat the joint by positioning the first bone withrespect to the second bone, by removing a bone core from the first bonealong a first axis to provide a bone core hole beginning in a firstregion of the first bone and approaching the first articular surface ofthe first bone without penetrating its articular surface wherein thefirst region is its non-articular surface, by performing an interventionthrough the bone core hole, and by replacing at least portion of thefirst bone core within the bone core hole. Such intervention may beimplanting at least one component of a prosthetic device within thefirst bone core hole.

[0009] Alternatively, the method may be provided for treating the jointby positioning the first bone with respect to the second bone, bycutting the first bone starting from its first region (e.g., the firstnon-articular surface thereof) and approaching its first articularsurface, and by ceasing cutting at a point adjacent the first articularsurface without penetrating it, thereby providing the first bone with anelongated first core hole capable of receiving an implant. The firstregion is generally the first non-articular surface of the first boneand, preferably, superficial to a surface of a body part such as limbs.

[0010] In another aspect of the invention, an access is provided to thejoint including at least one more-accessible bone, at least oneless-accessible bone, and the surrounding anatomical structures bypositioning the more-accessible bone with respect to the less-accessiblebone, by cutting the more-accessible bone starting from a first regionand approaching its articular surface, wherein the first region is itsnon-articular surface, and by ceasing cutting at a point adjacent thearticular surface of the more-accessible bone without penetrating it.Accordingly, the more-accessible bone is provided with a more-accessiblecore hole providing the access to a portion of the more-accessible bonewhich is substantially proximate to its articular surface.

[0011] In the alternative, a method may also be provided for an accessto the joint by positioning the first bone with respect to the secondbone, cutting out a core portion of the first bone starting from thefirst non-articular surface of the first bone and approaching the firstarticular surface of the first bone, where the core portion of the firstbone is not coupled to the surrounding anatomical structures of thejoint, and by ceasing cutting at a point adjacent the first articularsurface of the first bone without penetrating it. Therefore, withoutdetaching the surrounding anatomical structures from the first bone, thefirst bone can be provided with a first core hole configured to receivean implant.

[0012] In yet another aspect of the invention, a method for providing anaccess to the joint by positioning the first bone with respect to thesecond bone, by incising at most a portion of the joint capsule, bycutting out a core portion of the first bone starting from an exteriorportion of the first bone and approaching an interior portion of thefirst bone, and ceasing cutting at a point of the first bone disposedinside the joint capsule. Thus, without substantially compromisingintegrity of the joint capsule, the first core hole can be provided tothe first bone. A skin, fascia, fat layer, and/or soft tissues disposedon or adjacent the exposed portion of the first bone may be incised anda muscle may be divided in a direction of its main fibers. Blood vesselsand nerves may also be disposed away from the exposed portion of thefirst bone.

[0013] In another aspect of the invention, a method is provided fortreating a joint by positioning the first bone with respect to thesecond bone, by cutting a hole in the first bone along a first axisbeginning in the first bone first region and passing through the firstbone articular surface, by continuing cutting the hole through thesecond bone articular surface and into the second bone, by terminatingcutting of the hole within the second bone, and by implanting at leastone component of a prosthetic device within the second bone hole bypassing the component through the first bone hole.

[0014] In a further aspect, another method is provided for treating ajoint by positioning the first bone with respect to the second bone, bycutting a hole having a first diameter in the first bone along a firstaxis beginning in the first bone first region and passing through thefirst bone articular surface, by continuing cutting the hole through thesecond bone articular surface and into the second bone, by enlarging thehole to a second diameter greater than the first diameter at a locationspaced away from the first bone first region, and by implanting at leastone component of a prosthetic device within the enlarged hole by passingthe component through the hole with the first diameter.

[0015] The present invention further provides various orthopedicimplants (including implant assemblies and modules thereof) for thetransosseous core method and devices therefor.

[0016] In one aspect of the invention, an orthopedic implant assembly isprovided which is arranged to be implanted adjacent to or in the jointthrough a pathway formed inside the joint bone and having an effectivepathway dimension. Such implant assembly includes at least two implantmodules each of which is configured to have an effective moduledimension no greater than the effective pathway dimension so as to allowpassage of the implant module through the pathway. Each implant moduleis configured to couple with at least one of the others to form theimplant assembly in situ having an effective assembly dimension which isno less than both of the effective pathway dimension and effectivemodule dimension.

[0017] In another aspect, a surgical kit is provided to include a bonecutting tool having a cutting element for creating a bone hole of afirst diameter, and a bone prosthesis assembly with at least two implantmodules configured and dimensioned to be separately inserted through thebone hole of the first diameter and to mate together at a site ofinterest to form said assembly. The surgical kit also includes asurgical hemostat for treating the wall of the bone hole. The hemostatcomprises an applicator expandable from a retracted position to aexpanded position, a cylindrical, expandable sleeve configured anddimensioned to be disposed over the applicator in the retractedposition, and a hemostatic agent disposed on the sleeve, where expansionof the applicator to the expanded position within a bone hole forces thehemostatic agent against the wall. The surgical kit further includes acartilage punch having an operative portion configured and dimensionedto be inserted through the first diameter bone hole and manipulated fromoutside the hole, where the operative portion typically includes a bladewhich surrounds a central cavity to capture cartilage cut by said blade.The surgical kit may further includes a second bone cutting tool with anoperative portion configured and dimensioned to be inserted through thefirst diameter bone hole and manipulated from outside the hole, wherethe operative portion includes at least one cutting member for removingbone material to provide a larger void within the first diameter bonehole.

[0018] In another aspect, a prosthetic assembly is provided to beinserted through a bone hole having a first hole diameter and implantedat a site of interest within a bone or joint. The assembly includes atleast two implant modules configured and dimensioned to be individuallyinserted through the bone hole and the implant modules fit together atthe site of interest to form said prosthetic assembly. When assembled,the assembly has at least one dimension larger that the first holediameter.

[0019] A surgical tool is also provided for cutting bone and includes anelongated body and a cutting member. The elongated body has alongitudinal axis and defining an opening in a distal portion thereofand the cutting member is movably disposed within the body so that thecutting member moves between a first position disposed within the bodyand a second position extending out of the opening for cutting bone.

[0020] In another aspect, a surgical hemostat is provided for treatingwalls of bone holes. Such hemostat typically includes an applicatorexpandable from a retracted position to a expanded position, acylindrical, expandable sleeve configured and dimensioned to be disposedover the applicator in the retracted position, and a hemostatic agentdisposed on an outer surface of the sleeve. When the applicator isexpanded to the expanded position within a bone hole, the hemostaticagent is forced against the bone hole wall.

[0021] In a further aspect, an expandable surgical bone reamer includesa central member, a plurality of arms extending radially from thecentral member where the arms are extensible in the radial directionbetween retracted and expanded positions, a bone reaming member disposedon each arm opposite the central member, and an expansion mechanismoperatively connected to the arms such that the distance of the bonereaming members from said central member may be controlled.

[0022] Other features and advantages of the present invention will beapparent from the following detailed description, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023]FIG. 1 is a schematic view of joint bones and surroundinganatomical structures of an exemplary joint;

[0024]FIG. 2A to 2R are schematic diagrams of the joint bones treated byexemplary transosseous core approaches according to the presentinvention;

[0025]FIG. 3 is a schematic cross-sectional view of an initial step ofthe transosseous core approach and exemplary instrumentation fortreating a shoulder joint according to the present invention;

[0026]FIGS. 4A to 4C are views of an exemplary guide assembly accordingto the present invention;

[0027]FIG. 5 is a schematic cross-sectional view illustrating a corecutting step and exemplary instrumentation therefor according to thepresent invention;

[0028]FIG. 6 is a cross-sectional view of an exemplary core cutteraccording to the present invention;

[0029]FIG. 7 is a schematic cross-sectional view illustrating acartilage punching step and exemplary instrumentation therefor accordingto the present invention;

[0030]FIG. 8 is a cross-sectional view of an exemplary cartilage punchaccording to the present invention;

[0031]FIGS. 9A and 9B are perspective views of an exemplary hemostasisdevice according to the present invention;

[0032]FIG. 10 is a schematic cross-sectional view illustrating abone-reaming step and exemplary instrumentation therefor according tothe present invention;

[0033]FIG. 11 is a schematic cross-sectional view illustrating the stepof implanting an exemplary glenoid prosthesis according to the presentinvention;

[0034]FIG. 12 is a side view of an exemplary glenoid implant as shown inFIG. 11;

[0035]FIG. 12B is a cross-sectional view of a reamer according to thepresent invention;

[0036]FIG. 12C is a perspective view of an expandable reamer accordingto the invention; FIGS. 13A and 13B are schematic cross-sectional viewsillustrating the steps of providing exemplary auxiliary holes in thefirst bone and exemplary instrumentation therefor according to thepresent invention;

[0037]FIGS. 14A and 14B are cross-sectional views of an exemplary angledreamer suitable for providing auxiliary holes as shown in FIGS. 13A and13B according to the present invention;

[0038]FIGS. 15 and 16 are schematic views illustrating an implantinserting step and exemplary instrumentation therefor according to thepresent invention;

[0039]FIG. 17A is a side view of one embodiment of a joint-resurfacingimplant according to the invention;

[0040]FIGS. 17B to 17D are perspective views of alternative embodimentsof joint-resurfacing implant assemblies according to the presentinvention;

[0041]FIG. 18 is a schematic cross-sectional view illustrating anintramedullary canal and a component of an exemplary modular stem withinthe canal according to the present invention;

[0042]FIG. 19 is a schematic cross-sectional view illustrating animplant assembly of FIG. 18 for shoulder replacement according to anexemplary embodiment of the present invention;

[0043]FIG. 20 is a schematic cross-sectional view illustrating onembodiment of a total hip prosthesis as implanted according to thepresent invention;

[0044]FIG. 21 is perspective view of an acetabular implant according toan embodiment of the present invention;

[0045]FIG. 22 is a cross-sectional perspective view of the acetabularimplant shown in FIG. 21;

[0046]FIG. 23 is a perspective view of an axial retractable cuttingdevice according to an embodiment of the present invention; and

[0047]FIG. 24 is a perspective view of an transaxial retractable cuttingdevice according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] The present invention can be used to treat problems that occur inalmost any joint, in particular diarthroidal joints. A common element orfeature of the present invention, regardless of which joint is treated,is that the joint surface(s) to be treated are approached through afirst bone, i.e., the transversed bone. This is accomplished by creatingan exposure through a channel or hole that is made in the transversedbone overlying the joint surface to be addressed. Preferably, thechannel is made by a transosseous core, which core can be replaced aftertreatment or placement of an implant to reconstitute the integrity ofthe bone substance or surface. In this manner, the joint surface to betreated is approached from the “back side” such that highly invasivedislocation of the joint and wide exposure incisions are not required tocreate the necessary access. Depending upon the degree of treatmentnecessary, the present invention also avoids or minimizes in appropriatecases disruption of the capsule and other soft tissue structuresassociated with the joint. As a further aspect of the present invention,special implants and associated instrumentation are devised to take fulladvantage of this less invasive approach.

[0049] The transosseous core approach according to the invention can beapplied to many joints of the body for a variety of purposes. FIGS. 2Ato 2R are schematic diagrams of the transosseous core approach accordingto the present invention, in which details of the anatomical structuresof the joint are omitted for simplicity so as to provide an overview ofdifferent applications of the transosseous core approach. FIGS. 2Athrough 2K show only first bone “A”, typically a more readily accessiblebone, while FIGS. 2L through 2R only show second bone “B”, typically aless accessible bone.

[0050] As shown in FIG. 2A, first bone A is preferably cored startingfrom a first region (i.e., the non-articular surface of the first boneor “first non-articular surface”, 8A in FIG. 1) and approaching thearticular surface thereof (“first articular surface”, 1A in FIG. 1).Typically the first bone hole will have a diameter approximately 10% to30% of the bone diameter at the site of the hole. If desired, thecutting process may be stopped at any point near or adjacent the firstarticular surface before cutting or penetrating such. Accordingly, thefirst bone is provided with a generally elongated first pathway or firstcore hole (designated as “CH1” in the figures) into which one or moreimplants may be inserted and secured. The first non-articular surface 8Ais preferably superficial to a surface of a body part such asextremities and, therefore is more accessible to a surgeon forcommencing drilling the first bone.

[0051] Once the first core hole is cut, one or more auxiliary holes(“first auxiliary hole” referred to as “AH 1” in the figures) may beprovided in a second region of the first bone. As in FIG. 2B, the secondregion may be an uncut portion of the first non-articular surface fromwhich the first auxiliary hole may be drilled toward an interior of thefirst core hole (e.g., FIG. 2F) or toward other uncut portions of thefirst bone including both the non-articular and articular surfacesthereof. If desirable, the second region may also be an uncut portion ofthe first articular surface. As shown in FIG. 2D, the second region maybe an interior of the first core hole from which the first auxiliaryhole may be extended toward the uncut portion of the first bone whichmay be either non-articular or articular surface thereof. In thealternative, as shown in FIG. 2H, the second region may be an entranceof the first core hole (i.e., the first region or the cut-outnon-articular surface) or may lie in a region between the uncut portionof the first non-articular surface and the entrance of the first corehole. The first auxiliary hole may then be drilled toward the interiorof the first core hole (e.g., to enlarge the diameter of an entrance,interior, and/or exit of the first core hole) or the other uncutportions of the first bone.

[0052] The cutting may be continued in the first bone to extend thefirst core hole to the first articular surface, and a core portion ofthe first articular surface may then be removed through or cut outaround the first core hole, thereby providing the first bone with afirst core opening (FIGS. 2C, 2E, 2F, 2J, and 2K). Similarly, thecutting may be continued in the first bone to extend the first auxiliaryhole toward the first non-articular surface (FIGS. 2E, 2F, and 2G),toward the first articular surface (FIGS. 2I, and 2J), toward theinterior of the first core hole (FIGS. 2C, 2F, and 2G), and toward otherregions of the first bone. An auxiliary portion of the first articularsurface may also be drilled through or cut out around the firstauxiliary hole, thereby providing the first bone with a first auxiliaryopening. The first core and auxiliary holes may be spaced apart (FIG.2C) or arranged to communicate with each other (FIGS. 2E to 2G, 2I, and2J). The first core and auxiliary holes may also be arranged at angles(FIGS. 2C, 2E to 2G, 2I, and 2J) or parallel with each other (notshown). As described in greater detail below, it will be appreciated bypersons of skill in the art that the general techniques described forforming auxiliary holes from the first core hole also may be used toresect all or a portion of the bone end.

[0053] Once at least the core opening is provided in the first bone asshown in FIGS. 2C, 2E to 2G, and 2I to 2K, the articular surfaces of thefirst and/or second bones or the anatomical structures of the joint maybe treated by pharmaceutical agents, fluid agents, and/or surgicaltools. If desired, one or more implants may be inserted and secured tosuch holes. The cut-out portions of the first articular surface and/orbone core may be reimplanted. After the first core and/or auxiliaryholes are provided in the first bone as exemplified in any of FIGS. 2Ato 2K, if there is a need to treat the second bone or to place animplant therein, the second bone may be cut according to any of theconfigurations shown in FIGS. 2L to 2R. FIGS. 2L through 2R correspondto various transosseous core approaches where the first bone is providedwith the first core hole traversing the entire length of the first boneand optionally with first auxiliary holes.

[0054] In FIG. 2L, the articular surface of the second bone (“secondarticular surface”) is drilled through or cut out in its first regionwhich is disposed substantially opposite to the first core opening,thereby providing the second bone with a second core opening. A coreportion of the second bone is then cut out further into its interioruntil it reaches a desirable depth, thereby providing the second bonewith a second core hole (designated as “CH2” in the figures) configuredto receive an implant. The second core hole is generally cut out in linewith the first core hole (e.g., FIGS. 2L, 2N, and 2P to 2R) so that bothcore holes define a substantially straight pathway for the tools orimplants such as magnetic arrays, orthopedic prostheses, pharmaceuticalor fluid agent delivery systems, mechanical superstructures, and/orsurgical prostheses. However, as shown in FIGS. 2M and 2O, the secondcore hole may be cut in an angle with respect to the first core hole byusing, e.g., an angled cutting tool which will be discussed in greaterbelow (see FIGS. 14A and 14B).

[0055] One or more auxiliary holes also may be created in a secondregion of the second bone (“second auxiliary hole” referred to as “AH2”in the figures). In FIG. 2N, the second region is an entrance of thesecond core hole (i.e., the second region or the cut-out articularsurface of the second bone) from which the second auxiliary hole may beextended toward the uncut portion of the second bone such as the secondnon-articular surface or interior thereof. As shown in FIGS. 2P and 2Q,the second region may also be an interior of the second core hole, andthe second auxiliary hole may be cut toward the uncut portion of thesecond bone. In the alternative, as shown in FIG. 20, the second regionmay lie in a region between the uncut portion of the second articularsurface and the entrance of the second core hole. The second auxiliaryhole may be drilled toward the interior of the second core hole or theother uncut portions of the second bone. Furthermore, as in FIGS. 2Q and2R, the second region may be an uncut portion of the non-articularsurface of the second bone (“second non-articular surface”) from whichthe second auxiliary hole may be drilled toward an interior of thesecond core hole or toward the uncut portion of the second bone. Anauxiliary portion of the second articular surface may also be drilledthrough or cut out around the second auxiliary hole, thereby providingthe second bone with a second auxiliary opening. The second core andauxiliary holes may be spaced apart (FIG. 2R) or arranged to communicatewith each other (FIGS. 2N to 2Q). The second core hole and auxiliaryholes may also be arranged at angles (FIGS. 2N to 2R) or parallel witheach other (not shown). Once again, utilizing the techniques herein, thesecond bone may be resected through the first core hole.

[0056] Once the core and/or auxiliary openings are provided in thesecond bone, the second articular surface or the anatomical structuresof the joint may be treated and, if preferred, the implant may beinserted into and secured to the holes. The cut-out portions of thesecond articular surface and/or bone core may also be reimplanted ifappropriate.

[0057] Before beginning a transosseous core procedure according to theinvention, the patient is properly positioned (e.g., seated or inclinedwith or without relative traction for treating the shoulder joint) toprovide access to and proper alignment of the bones of the joint to beoperated on. Careful placement of the patient on the operating table andpositioning of the joint to be operated on will facilitate the sequenceof steps to be performed. For example, various holding devices may bemovably or fixedly attached to a stable operation table. Specific partsof a patient may be linked to the holding device and/or operating tableby utilizing surface anatomy and through conventional fixation methodsemploying, e.g., calipers, pins, clamps with inflatable bladders, andthe like. Other holding means or their modifications may be used in thetransosseous core approach so long as they allow the joint bones to bereadily movable and positioned without excessive restriction. Forexample, the holding device is preferably constructed to allow the jointto be mobile in flexion/extension, abduction/adduction, rotation, and/orthree-dimensional translation. Such holding devices may be directedtoward translatory support during specific phases of the surgicalprocedures or may be configured to provide continued and sustainedpositioning that may be occasionally readjusted. Additional positioningfeatures may also be incorporated to the holding devices for preciseadjustment thereof so that the surgeon may manipulate each degree offreedom separately to achieve the final desired position of the joint tobe operated on.

[0058] In order to further illustrate the present invention, anexemplary embodiment is described using a model of a large joint, inparticular, the shoulder joint. A person of ordinary skill in the artwill recognize that the principles, techniques and devices disclosedherein may also be readily adapted to be used in other joints withoutdeparting from the scope of the present invention.

[0059] After being properly positioned on the operating table, thepatient is prepared and draped in the normal sterile fashion. As shownin FIG. 3, bone “A” is a humerus, while bone “B” is a scapula or, moreparticularly, the glenoid thereof. Bone “A” is also generally the “firsttransversed bone,” “first bone” or “more accessible bone,” while bone“B” is the “second adjacent bone,” “second bone” or “less accessiblebone.”

[0060] Preoperatively, the surgeon utilizes X-rays CAT scan or MRI toview the bone and surrounding tissues to be operated, e.g., a humerus,humeral head, and glenoid for the shoulder joint. Based on these images,the surgeon makes exact measurements of the joint configurations, e.g.,such as relative retroversions of the humeral head with respect toepicondyles of the humerus. The surgeon also determines an optimum drilldepth for the humeral head and/or glenoid, size of the core hole(s),core depth, size of the implant such as core and auxiliary implants,axial rods, trans-prostheses, etc. The size and angle of retroversionmay also be confirmed between the glenoid neck and the glenoid itself.By utilizing various positioning features of a holding device, thesurgeon identifies an optimal position of the humeral head and glenoidfor treatment, e.g., a position of 30° abduction and 30° externalrotation in case of the shoulder joint. An AP radiograph is taken oncethe patient is positioned to verify relative orientation of the bones.Based on the MRI images, the surgeon may also check the surroundinganatomical structures such as vasculature, supracapular nerves, muscles,ligaments, and other soft tissues disposed adjacent or surrounding thejoint.

[0061] After the patient's upper shoulder and chest are prepared anddraped, a small incision or stab wound is made, e.g., along themid-lateral vertical direction, about one centimeter inferior to thelateral border of the acromion, and dissection is performed fromsubcutaneous tissues to the deltoid. A suture is placed in the inferiorlimit of the separation of the deltoid muscle in order to preventundesirable dissection which may endanger the axilliary nerve. Thedeltoid is then divided in the direction of fibers and a cylindricalretractor may be placed thereon to expose a pre-selected portion of thefirst bone (e.g., non-articular surface such as the lateral humerus).Referring again to FIG. 3, a guide wire or pin 10 is then insertedthrough a region inferior to the suprascapular attachment. Guide wire 10is then drilled into the first bone to an appropriate depth atappropriate angles with respect to the axes of the first transverse boneon the X-Y and X-Z planes (e.g., axial, sagittal, coronal, and/orlateral directions) so that it is centered in the head. For example,depending on the objective of the intervention, guide wire 10 may beplaced into interior of the first bone, through the first articularsurface of the first bone, and into the interior of the second bonethrough the second articular surface of the second bone. The position ofguide wire 10 may be confirmed using at least two orthogonalinteroperative radiographic views.

[0062] As shown in FIG. 3, guide assembly 12 is placed over guide wire10 and inserted through the wound while repositioning blood vessels,nerves, ligaments, muscles, tendons or other soft tissues surroundingthe joint so that they are not trapped inside guide assembly 12. Ifnecessary, blood vessels or sensory branches of nerves may be divided aswell. Following placement of guide assembly 12, additional pins 14 maybe placed through pin guide 25 so as to hold guide assembly 12 in place.Guide wire 10 and pins 14 are preferably made of a material such asstainless steel having appropriate mechanical strength and may be shapedand sized to be easily inserted through the anatomical structuressurrounding the joint.

[0063] Guide assembly 12 generally includes an obturator and a drillguide, where the obturator is preferably movably disposed inside thedrill guide. FIGS. 4A to 4C are views of an exemplary guide assembly 12according to the present invention, where FIG. 4A is a side view of anexemplary obturator 16 and where FIGS. 4B and 4C are a side view and atop view of a matching drill guide 22, respectively.

[0064] Obturator 16 generally includes a cylindrical body 17 and definesan internal bore 18 which is formed along a central longitudinal axisthereof and shaped and sized to receive guide wire 10 therethrough. Adistal portion of obturator 16 is truncated to form a distal tip 19which may be pointed enough to be inserted around the anatomicalstructures surrounding the joint, but not sharp enough to cut, penetrateand/or otherwise destroy such, thereby clearing the site of insertionfrom unnecessary anatomical structures such as the soft tissues. Acircular flange 20 is also attached to a proximal portion of obturator16 and arranged to have a diameter greater than that of obturator body17.

[0065] Drill guide 22 generally includes an annular cylindrical body 23which couples with an annular flange 24 at its distal portion. Annularguide body 23 is generally arranged to receive cylindrical body 17 ofobturator 16 therethrough. Thus, annular guide body 23 is sized to havean inner diameter which is slightly greater than the outer diameter ofobturator body 17. Annular guide flange 24 also has an inner diametergreater than that of obturator body 17 but less than the outer diameterof circular obturator flange 20. Therefore, when obturator 16 isinserted into drill guide 22, cylindrical annular body 23 allowslongitudinal translation of obturator 16 up to a position where annularguide flange 24 abuts a distal step 21 of obturator flange 20 andprevents further translation of obturator 16. Annular guide body 23and/or guide flange 24 also define multiple longitudinal bores 25 aroundcircumference thereof which are configured to receive additionalpositioning or anchoring pins 14 therethrough. For example, drill guide22 exemplified in FIGS. 4B and 4C includes four identical bores 25distributed at every 900 around annular guide flange 24 through anentire length of annular guide body 23.

[0066] As shown in FIG. 5, once drill guide 22 is properly positionedand secured in place, obturator 16 is removed from drill guide 22retrogradely and core cutter 30 is inserted therein to cut and remove acore from the first bone, i.e., the humeral head. As will be explainedin greater detail below, the first core hole may continue through thefirst articular surface of the first bone by cutting out a first coreportion of the first articular surface. Various implants may be disposedin the first core hole, e.g., to replace or augment one or entireportion of contour of the first articular surface of the first bone(i.e., resurfacing implants) or to generate or manipulate mechanicalinteraction between the first articular surface of the first bone andthe opposing second articular surface of the second bone (i.e.,non-resurfacing implants). The first core hole may also be used toprovide access for repairing soft tissues, repairing, removing orreplacing cartilage, arthroplasty, removing or repairing bones orreattaching the glenoid labrum, and the like. Examples of resurfacingand non-resurfacing implants are disclosed in detail in co-pending U.S.patent application Ser. No. 09/594,356, entitled “Magnetic ArrayImplant” (“the '356 application”) which is incorporated by referenceherein in its entirety.

[0067] The diameter of the first core hole is dictated by many factorsincluding, e.g., the size of the first bone, configuration of the firstbone in its transverse position, shape and size of a particular implantto be inserted and secured to the surrounding anatomical structures, andthe like. Therefore, core cutter 30 is generally specifically designedfor use with implants having specific configurations. The depth to whichthe first core is cut into the first bone also depends upon the factorsdescribed above. In procedures where the first core hole is to receive ajoint resurfacing implant, the first core hole preferably continuesthrough the first articular surface of the first bone by cutting out afirst core portion of the first articular surface. However, insituations where a non-resurfacing implant is to be used, the first corehole may stop appreciably or immediately before the first articularsurface of the first bone. Other implants and prostheses may also beemployed. Magnetic or non-magnetic resurfacing implants may be used toform a portion of the first articular surface. When the first bone isstructurally compromised and, therefore, includes multiple boneportions, nonmagnetic prosthesis or magnetic assemblies may providemechanical integrity to the first bone. In addition, a drug or agentdelivery system may be inserted into the bone to perform eitherpharmaceutical or Theological interventions in the joint. For example, apharmaceutical or Theological agent may be injected directly from theagent delivery system or introduced via a carrier medium for inducingpharmacological intervention for treating the bones, their articularsurfaces or other anatomical structures surrounding the joint. Steroids,antibiotics, antiviral pharmaceuticals, radioactive isotopes, andchemotherapeutics are typical examples of such pharmaceutical agents. Afluid agent such as hyluronic acid-based liquids may also be injecteddirectly to the joint so as to provide lubrication between the articularsurfaces, and/or other viscous liquids may be injected to absorb shockstransmitted through the joint bones.

[0068] Although the first hole of the first bone may be drilled throughby a drill bit and the bone material and/or cartilage separated from thebone may be removed through a proximal portion of drill guide 22, a holesaw is preferably used to provide a bone core that may be preserved andreimplanted back at the first core hole after repairing, replacing ortreating the joint. Therefore, the transosseous core approach of thepresent invention preferably employs an annular core cutter as shown inFIG. 6 for preserving at least a portion of the first bone core. Corecutter 30 typically includes an elongated cylindrical shaft 31, annularcutting element 32 with multiple cutting teeth 33 disposed at a distalportion thereof, and connector 34 for mechanically coupling annularcutting element 32 to shaft 31. Shaft 31 is arranged to couple with anoscillation or rotation device (not shown) so that oscillatory orrotational motion of the device is delivered to cutting element 32through connector 34. Cutting element 32 is typically shaped as anannular cylinder which is open at its distal end 39 and which includes acircular base 35 at its proximal end. Shaft 31, connector 34, and base35 are preferably arranged to define a bore 36 formed along alongitudinal axis of core cutter 30 and arranged to receive guide wire10 therethrough so that core cutter 30 is guided therealong. Annularcutting element 32 may be made of high-strength material so thatthickness of circumferential wall and cutting teeth 33 can be maintainedat their minimum. Such an embodiment minimizes loss of bone during thecutting process.

[0069] An auxiliary drill shaft 37 may be provided inside annularcutting element 32 to provide mechanical strength to core cutter 30 formaintaining its shape and/or integrity as well as to provide a centralhole for discharging debris and/or supplying irrigation fluid during thecutting process. The length of auxiliary drill shaft 37 may varydepending on the need, e.g., shorter than that of annular cuttingelement 32 or longer so that a distal tip 38 of auxiliary drill shaft 37slightly extends out of distal end 39 of annular cutting element 32.Distal tip 38 of auxiliary drill shaft 37 may be pointed to facilitateanchoring of core cutter 30 during the cutting process. Auxiliary drillshaft 37,may also be provided with cutting edges or teeth which mayfacilitate drilling a center portion of the first bone core.

[0070] Similar to the case of drill guide 22, the optimal shape and sizeof core cutter 30 are a matter of selection of those skilled in the art,and generally determined by various factors including, e.g., the size ofthe first bone, configuration of the first bone in the transverseposition, size of the resurfacing and/or non-resurfacing implant to beused, and the like. In the exemplary embodiment of the shoulder joint, acore cutter for providing the first core hole of one inch in diametermay include an annular cutting element of about two inches in length,about one inch in diameter, and about 0.2 mm to 1.5 mm in wallthickness. Each cutting tooth may have a width of about 0.5 mm or less.The auxiliary drill shaft may have a diameter ranging from about 2 mm to20 mm, e.g., more preferably about 6 mm to 7 mm. It is appreciated thatthe above configuration of the core cutter may be adjusted by personsskilled in the art, e.g., according to a desired diameter and depth ofthe first core hole, shape and size of the implant to be used, and thelike. After reaching a desired depth, core cutter 30 is removed fromdrill guide 22 along with the first bone core at least a portion ofwhich may be preserved for later reimplantation thereof into the firstcore hole.

[0071] If the cartilage surface is to be reimplanted, after removingcore cutter 30, a cartilage punch 40 is inserted through drill guide 22as shown in FIG. 7. Cartilage punch 40 may be driven, oscillated orrotated to cut out a core portion of the first articular surface of thefirst bone and to provide the first core opening to the first bone. Ifpreferred, the previous core cutting step may be terminated at a certaindistance from the first articular surface such that at least a minimumthickness of the first bone is attached to the cartilage to preserve itsmechanical integrity and physiological viability.

[0072] If the cartilage is damaged and/or non-functional, it may bedrilled away by drill bits and discarded. Alternatively, a cartilage maybe carefully incised, preserved, and reimplanted back at the firstarticular surface after repairing, replacing or treating the joint.However, because the cartilage is generally thin and sometimesinseparable from the residual bone attached thereto, a complex of thecartilage and bone (“cartilage-bone autograft” or simply “cartilage”hereinafter). As shown in FIG. 8, cartilage punch 40 is preferablydesigned to minimize the damage to the removed cartilage (orcartilage-bone autograft) to the extent possible. Cartilage punch 40resembles core cutter 30 in many respects, e.g., including an elongatedshaft 41, a blade 42 with a circular cutting edge 43 disposed at adistal portion thereof, and a connector 44 for mechanically couplingannular punch blade 42 to shaft 41. However, circular cutting edge 43 ofcartilage punch 40 preferably has a thickness which may be substantiallyless than core cutting teeth 33 so that the portion of cartilage lostduring the punching process may be minimized. An exemplary range of thethickness of cutting edge 43 is from about 0.2 mm to 1.0 mm, e.g., about0.3 mm. In addition, blade 42 and cutting edge 43 are preferably made ofhigh-strength material so that the first bone attached to the cartilagemay be punched out and removed with the first articular surface thereby.In general, an upper limit of the diameter of annular blade 42 may bedetermined by a maximum diameter of the cut-out portion of the articularsurface that would present negligible or minimal chance of damaging orinterfering with other joint structures, e.g., in the range of up to fewinches, preferably about 0.5″ to 1.5″. When the cartilage-bone complexis cut out using cutting blade 42 having the foregoing dimensions, theportion of the cartilage lost during the cutting process approximatelyamounts to 12 mm². The cut-out portion of the first articular surface orcartilage-bone autograft tends to be tightly fit around cutting edge 43and, therefore, may pose difficulty in harvesting it without inflictingdamages thereon. Accordingly, an opening 45 may be provided to connector44 to allow a push rod to be inserted and to push the cut-out articularsurface out of cutting edge 43. Alternatively, shaft 41 may be arrangedto be pulled out of connector 44 and the push rod may be insertedtherethrough.

[0073] In some procedures, hemostasis of a bleeding bone (e.g., from thebone core hole) may be required. Hemostasis can be accomplishedaccording to standard methods to reduce bone bleeding or by usinghemostasis device 60 according to the present invention. As shown inFIGS. 9A and 9D, hemostasis device 60 according to the present inventionincludes an expansion element 61, a handle 63, a support 64, andhemostatic agent 65. In particular, FIG. 9A shows hemostasis device 60in its retracted position. In this embodiment hemostatic agent 65comprises beeswax shaped as an annular sleeve. As best seen in FIG. 9B,expansion element 61 comprises multiple elongated side members 62 eachof which is movably coupled with shaft 64. Expansion element 61 isarranged to expand and retract in a radial direction between theexpanded position and the retracted position by radial displacement ofside members 62. Support 64 is generally a hollow cylinder with multipleradial arms and forms a grip 66 at its proximal end for ease of handlingand operation. Handle 63 is movably inserted through a bore of support64. Hemostatic agent 65 is shaped and sized to be placed over expansionelement 61 and mounted thereon.

[0074] In operation, expansion element 61 is moved to its retractedposition and covered by hemostatic agent 65. Hemostasis device 60 isinserted through drill guide 22, and positioned adjacent to surfaces ofthe bone hole where bleeding is to be stopped. While maintaining theposition of hemostatic device 60, an operator pushes handle 63 distallyso that expansion element 61 is triggered to expand in the radialdirection toward its expanded position. Hemostatic agent 65 then deformsand stretches with expanding expansion element 61 until it contacts thesurfaces of the bleeding bone. After the beeswax contacts the bleedingsurfaces, the operator may further push handle 63 so that side members62 of expansion element 61 firmly spread hemostatic agent 65 over thebleeding surfaces and/or smear the agent into pores of the bleedingsurfaces. After obtaining hemostasis, the operator releases handle 63 sothat the retraction mechanism pulls in side members 62 of expansionelement 61 to the retracted position. Hemostasis device 60 is thenpulled back through drill guide 22.

[0075] Persons of ordinary skill in the art may devise any number ofsuitable expansion mechanisms for such hemostasis devices. Examples ofsuch expansion mechanism may include, but not limited to, a springrelease mechanism, a screw based mechanism, and their functionalequivalents which may include manual, pneumatic or hydraulic engaging ordisengaging mechanisms. Various hemostatic materials may be used in thehemostasis device as long as such materials can directly or indirectlyinduce hemostasis by, e.g., physically and/or pharmacologically blockingbleeding from the bone holes or physiologically constricting blood flowtherefrom. Examples of the hemostatic materials may include, but notlimited to, beeswax, a mixture of gelfoam and thrombin, and the like.Hemostatic materials may also be provided in various forms, e.g., as acylindrical bar, single trough or multiple rounds.

[0076] Once adequate hemostasis is achieved, the surgeon may treat thejoint or the second bone. Alternatively, the surgeon may insert, throughdrill guide 22, one or more resurfacing or non-resurfacing implants aspreviously discussed. The above procedures may be repeated for insertionof additional implants to complete appropriate joint treatment asdescribed, e.g., in the co-pending '356 application.

[0077] Additional instrumentation (i.e., a specifically adaptedendoscope lens or camera with appropriate illumination devices) can beutilized to allow the surgeon to visualize the opposing articularsurface of the second adjacent bone and allow preparation of the secondbone (if necessary) to receive appropriate components. Additional entrysites may be provided if additional implants are to be used, e.g., asdescribed in the co-pending '356 application. Such implants may beimplanted by traditional techniques or the transosseous core approachdescribed herein above. These steps equally apply to the resurfacing andnon-resurfacing implants as well as the modules thereof.

[0078] The transosseous core approach of the present invention may alsobe completed after removing the first articular surface of the firstbone and placing resurfacing and/or non-resurfacing implants in thefirst core hole. For example, when the cartilage of the first bone needsto be removed and replaced by autograft, allograft, zenograft, and/orother replacements made of, e.g., metals, polymers, ceramics, etc., thecartilage may be punched out and such implants may be inserted at thecut-out portion of the cartilage to cover the cut-out opening of thefirst articular surface. The first bone core may then be reimplantedback at the first core hole, the first core hole closed (e.g., by thecut-out bone core may be harvested from the first and/or second bone)and the joint treatment may be terminated.

[0079] As discussed above, in situations where the joint treatmentrequires insertion of the resurfacing and/or non-resurfacing implants inthe opposing, second articular surface or an interior of the secondbone, the surgeon may continue with preparation of the second bone afterhemostasis is achieved to a satisfactory degree. The transosseous coreapproach under such circumstances permits cutting of the second bonecore hole(s) through the first bone core hole as described. Suchapproach may also be applied when a more-accessible bone of the joint isnot the one to be treated, i.e., when a cartilage of the more-accessiblebone is functionally operative, whereas an opposing cartilage of theless-accessible bone needs to be replaced or treated. After completingtreatment of the cartilage of the less-accessible bone by securing theresurfacing and/or non-resurfacing implants thereto, the cartilageand/or the bone core of the more- and/or less-accessible bone may bereimplanted at the articular surfaces and/or in the core holes tominimize post-surgical injury to the functionally operative joint.

[0080]FIG. 10 illustrates opening the pathway in the second boneaccording to the present invention. Reamer 70 is preferably insertedover guide wire 10 through drill guide 22 to cut a second core hole inthe second bone. Once again, the cutting element (e.g., reamer 70) ispreferably shaped and sized with the implants to be inserted in thesecond bone hole such that the cutting element has a cross-sectioncomplementary to that of the implants to be implanted in the secondbone. Alternatively, core cutter 30 may be again used to provide asecond core hole. Furthermore, when the second bone core is not to bereimplanted or when the glenoid implant is affixed to the second bone byconventional screws or adhesive components, other cutting tools known inthe art may also be used.

[0081] Once the second core hole is properly cut in the second bone, theresurfacing and/or non-resurfacing implant described above may beintroduced into the second bone through the first and second core holes.Preferably, at least the major components for resurfacing,non-resurfacing or joint-replacing implants are placed through thepathway created in the first bone. Accordingly, such implants preferablyhave dimensions allowing them to pass through the first core hole.Alternatively, as will be described in greater below, multiple implantmodules may be inserted through the first core hole and assembled insitu so that the assembled implant modules (i.e., “implant assembly”)have one or more final dimensions greater than those of the first corehole.

[0082]FIG. 11 illustrates placement of an exemplary second core implant(i.e., glenoid implant 80) in the second bone according to the presentinvention. In the figure, the first bone and second bone are denoted as“A” and “B,” respectively, and the first and second core holes as “C”and “D,” respectively.

[0083] One embodiment of glenoid implant 80, illustrated in FIG. 12A,generally includes structures for treating the joint and for securingitself to the second bone. For example, glenoid implant 80 includes atreatment layer 82 which is secured to a main body 84 thereof. Ifglenoid implant 80 is to be used as a resurfacing implant, bearingsurface 83 of treatment layer 82 is preferably contoured so that, uponimplantation, it can replace at least a portion of the second articularsurface of the second bone. Bearing surface 83 can be preferably made ofultra-high molecular-weight polyethylene. Other suitable polymers,metals, ceramics or materials that may reduce friction and wear andwhich yield little or no wear debris under the calculated load maybeused. However, when glenoid implant 80 is used as a non-resurfacingimplant, treatment layer 82 may include an array of magnets configuredto generate desirable magnetic fields therearound (e.g. as discussed inthe co-pending '356 application). Alternatively, treatment layer 82and/or body 84 may include a pharmaceutical delivery mechanism which maydirectly or indirectly induce desired pharmacological response in thejoint. Glenoid implant 80 also includes anchoring structures such asinterference fit surface 85B (e.g., a step cut or press fit) thatextends from body 84 and terminates as an anchoring screw 86 at itsdistal end. Alternatively, the main body of the implant may incorporatea tapered screw thread 85A as shown in FIG. 11. Anchoring screw 86generally serves as a guiding element for initially positioning glenoidimplant 80 at a desired position of the second core hole in a desirableorientation, whereas interference fit surfaces 85B or tapered thread 85Aprovides a greater contact area with the second bone and, therefore,helps to secure glenoid implant 80 to the second bone. In order toobtain desired orientation of glenoid implant 80 and to preventunintended rotation thereof, additional anchoring elements may beprovided as well. For example, the embodiment of FIG. 12A includes apair of side screws 87 protruding from interference surfaces 85B (ortapered screw 85A). Side screws 87 are inserted through cavities andbores provided in body 84.

[0084] For proper implantation of glenoid implant 80 with interferencesurfaces 85B, the second core hole is preferably shaped, such as byreaming, to match the profile of the implant. FIG. 12B shows anexemplary reamer 70 for this purpose. Tip 73 creates a small bore in thebone for anchoring screw 86. Step 74 provides a flat surface on the boneabutting a distal step 81 of glenoid implant 80. An angled side 75 ofreamer 70 offsets interference surfaces 85B or tapered screw 85A, etc.,to facilitate implantation of glenoidal implant 80. At the same time,reamer 70 ensures an adequate amount of the second bone to facilitatefixation of glenoidal implant 80.

[0085] In operation, glenoid implant 80 is inserted through the firstcore hole and its opening, and then placed at a location in the secondcore hole with or without treatment layer 82 attached thereto.Interference fit surfaces 86B are anchored into the second bone byrotating entire glenoid implant 80 or by rotating distal screw 86. Whentreatment layer 82 is not attached to body 84 of glenoid implant 80,side screws 87 may be directly inserted through bores 88 in the implantand anchored into the second bone. Treatment layer 82 is then insertedthrough the first and second core holes and secured to body 84 ofglenoid implant 80 at desirable orientation. Alternatively, treatmentlayer 82 may be provided with access holes (not shown) through whichside screws 87 may be inserted and secured to the second bone. In thisembodiment, side screws 87 may be retained inside body 84 and/or taperedscrew 85A with their distal tips retracted therein during the insertionof glenoid implant 80. After properly positioning and orienting glenoidimplant 80, side screws 87 are secured into the second bone.

[0086] If desired, reamer 70 may be arranged to cut the second core holehaving a shape and/or size different from those of the first core hole.For example, reamer 70 with a smaller cutting area may be used toprovide the second core hole smaller than the first core hole. Thisembodiment may generally be preferred when the second articular surfaceto be treated is smaller than the first core opening cut out in thefirst articular surface of the first bone or when the larger first corehole has to be made in the first bone due to various anatomical and/orinstrumental limitations.

[0087] In one alternative, a larger core hole may be cut in the secondbone by using a specially arranged cutting device incorporating anexpandable mechanism capable of providing a cutting area having adiameter greater than that of a main shaft of the cutting device. Thisembodiment is generally preferred when the second articular surface ofthe second bone to be treated is larger than the first core opening ofthe first bone, when the first core hole has to be made smaller becauseof the anatomical and/or instrumental limitations or when the largercore hole has to be cut in the second bone due to the similar reasons.FIG. 12C is a schematic diagram of an exemplary expandable reameraccording to the present invention.

[0088] Expandable reamer 71 typically includes a main shaft 76 and fourextendable arms 77 each of which includes a cutting device 78 at itsdistal end. Extendable arms 77 move between a retracted position and anextended position. In its retracted position, arms 77 are retracted sothat expandable reamer 71 as a diameter at least slightly less than thediameter of the first core hole to permit it to be inserted through thehole. In its expanded position, however, arms 77 extend distally so thatthe diameter of expandable reamer 71 increases beyond that of the firsthole. Expandable reamer 71 may include a pointed retractable distal tip79 to facilitate positioning thereof. Once again, expandable reamer 71is preferably shaped and sized with the implants to be inserted in thesecond bone such that it may have a cross-section in its extendedposition matching or offset to that of the implants to be implanted inthe second bone.

[0089] In particular procedures it may be necessary or desirable toremove an area of bone that is greater than the cross-sectional area ofthe bone core hole. This may be required, for example, to provideresurfacing over a full range of joint motion in some joints. Such alarger internal removal may be accomplished with an angled reamer suchas illustrated in FIGS. 13A, B and 14A, B. As shown in FIG. 13A angledreamer 90 is positioned through guide assembly 12 to cut a superior orfirst auxiliary hole. After cutting the superior auxiliary hole 96,reamer 90 is rotated to position it for cutting an opposite, inferior orsecond auxiliary hole as shown in FIG. 13B.

[0090] As illustrated in FIGS. 14A and 14B, one embodiment of angledreamer 90 according to the invention includes an annular cylindricalbody 91 including therein extendable shaft 92, cutting element 93, andpower transmission cable 94. Cutting element 93 is coupled to powertransmission cable 94 and arranged to transmit rotational powergenerated by a power source (not shown) to cutting element 93. Body 91includes a housing 95 arranged to receive and retain extendable shaft 92therein. Cutting element 93 is disposed at a distal end of extendableshaft 92 and movably supported thereby. Extendable shaft 92 adjusts itslength by moving between a retracted position (FIG. 14A) where cuttingelement 93 and shaft 92 are retained inside housing 95 and an extendedposition (FIG. 14B) where cutting element 93 extends out of housing 95by a desirable distance.

[0091] In operation, extendable shaft 92 is pulled into its retractedposition (FIG. 14A) so that an entire portion of extendable shaft 92 andcutting element 93 is retracted into housing 95. Angled reamer 90 isthen inserted through drill guide 22, and positioned inside the firstcore hole at a desired depth and orientation with respect to thelongitudinal axis of the first core hole. As shown in FIG. 14B, cuttingelement 93 is engaged and extendable shaft 92 gradually extends out ofhousing 95 toward its extended position, thereby forming an auxiliaryhole by removing bone at the angle set by housing 95 supporting cuttingelement 93. After a first auxiliary hole is cut to a desired depth,cutting element 93 is disengaged and extendable shaft 92 is pulled inagain to its retracted position along with cutting element 93. Angledreamer 90 is then may be rotated and reoriented, e.g., by 180° and, asshown in FIG. 13B, cutting element 93 is re-engaged, extendable shaft 92is extended, and second and/or subsequent auxiliary holes are created.

[0092] After auxiliary holes 96, 98 are drilled, core and auxiliaryimplants are inserted and secured as illustrated in FIGS. 15 and 16.First auxiliary implant (or implant module) 110 is first insertedthrough the first core hole and positioned in the first auxiliary hole96, followed by positioning of an second auxiliary implant 120 in thesecond auxiliary-hole 98. Positions of first and second implants 110,120 may be checked radiographically so as to leave a preselected spacetherebetween. Core implant 130 is then inserted through the first corehole and disposed between superior and inferior implants 110, 120.

[0093] As explained, first core implant 130 and auxiliary implants 110,120 are passed through the first core hole and then assembled in situ,thereby forming a first implant assembly having one or more dimensionsgreater than the first core hole. For this purpose, each of firstimplant modules 110, 120, 130 is provided with at least one couplingmechanism such as slots, screws, pins, magnets, or other couplingelements which may be devised by a person of ordinary skill in the art.Alternatively or additionally, each implant module 110, 120, 130 may beindividually secured to the first bone, or a first implant module may besecured to the first bone, while the other two modules secured to thefirst module. FIGS. 17A to 17D illustrate exemplary embodiments of theimplant assemblies according to the present invention.

[0094] In FIG. 17A, an exemplary implant assembly 101 includes firstimplant 110, second implant 120, and cylindrical core implant 130, whichis a substantially elongated cylinder having a diameter at leastslightly less than the internal diameter of the cylindrical first corehole. Core implant 130 has distal end 131 and proximal end 132, andincludes treatment layer 134 at its distal end, which is arranged toform a portion of the first articular surface, to interact with thesecond bone or to interact with an implant inserted in the second bone.First implant 110 is also shaped as a cylindrical rod but cut along anaxis which connects one edge of its distal portion 111 and a diagonallyopposing edge of its proximal portion 112 in such a way that a contouredinner surface of the truncated portion is concave to sung-fit anexternal surface of a side of main implant 130. Second implant 120 isalso shaped as a cut cylinder so that its concave inner surface matchesthe external surface of an opposing side of main implant 130. Implants110, 120 also include treatment layers 114, 124 which are arranged toperform the functions similar to treatment layer 134 of main implant130. Treatment layers 114, 124 are also preferably contoured to form asubstantially continuous contour with main implant 130. Therefore, whenassembled together, implants 110, 120, 130 form a mechanical surfacehaving a dimension substantially greater than the cross sectional areaof the first core hole.

[0095] It will be appreciated that implant assembly 101 of FIG. 17A isfunctionally the same as, but configurationally different from, implantassembly 102 of FIG. 16. That is, in the embodiment of FIG. 16,cylindrical main implant 130 defines an angled cylindrical internal bore135 commencing from proximal end 132, bifurcating into a pair of angledinternal bores, and culminating in opposing openings 136 into whichsuperior and inferior implants 110, 120 are inserted and secured.Therefore, implant assembly 102 of FIG. 16 is assembled by insertingmain implant 130 into the first core hole, followed by insertingsuperior and inferior implants 110, 120 through internal bore 135 andsecuring such implants 110, 120 to main implant 130 by securingmechanisms as discussed below.

[0096]FIG. 17B is a schematic view of another implant assembly 103according to the present invention. Exemplary implant assembly 103includes a pair of major implants (or implant modules) 141, 142 andanother pair of minor implants (or implant modules) 143, 144 secured atfour equi-spaced core and/or auxiliary holes provided around the firstcore hole in which main implant 130 is disposed. Each implant 130,141-144 is arranged so that, when put together, a distal portion ofimplant assembly 103 forms a quadra-foil bearing surface which may forma portion of the first articular surface and which is substantiallylarger than the cross-sectional area of the first core hole. Eachimplant 130, 141-144 may also include at its distal end the treatmentlayer identical or similar to those discussed above. Similar to theprevious implant assemblies and as shown in FIG. 17A, major and minorimplants 141-144 may be first implanted and then secured to theperipheral surface of main implant 130 inserted subsequently thereafter(as shown in FIG. 17B). Alternatively, main implant 130 may bepositioned in the first core hole, and major and minor implants 141-144may be inserted through an internal bore and four equi-spaced openingsof main implant 130 and subsequently secured to the first bone and/ormain implant 130. Furthermore, each of main, major, and minor implants130, 141-144 may be secured via a separate coupler (not shown) insertedthrough the first core hole so that the implant assembly maintains itsconfiguration through the coupling force between the coupler and eachimplants 130, 141-144.

[0097]FIG. 17C is a perspective view of yet another exemplary implantassembly 104 according to the present invention. Similar to theembodiment of FIG. 17B, implant assembly 104 includes main implant 130.In this embodiment, four substantially identical auxiliary implants 145are symmetrically disposed around implant 130. Treatment to surface 137of each individual implant module preferably has a spherical shape suchthat when assembled together implants 130, 145 form an overall treatmentsurface for implant assembly 104 corresponding to a surface of ahemisphere or. truncated hemisphere.

[0098]FIG. 17D is a perspective view of a further alternative implantassembly 105 according to the present invention. In this embodiment,implant assembly 105 includes three wedge-shaped implants (or implantmodules) 146 which are substantially identical to each other and to bealigned side by side to form the assembly 105. Preferably central wedge146 a is designed with a specific side contour so that outer wedges 146b and 146 c are mirror images of one another.

[0099] As discussed above, all auxiliary implants 110, 120, 141-146preferably include at least one coupling mechanism so that they cancouple to each other and/or with main implant 130 in situ to form theimplant assemblies 101-105. In general, incorporating an appropriatecoupling mechanism to the implant assemblies is a matter of selection ofthose skilled in the art. For example, each pair of adjoining implantsmay be arranged to have matching mechanical structures allowingmechanical coupling therebetween, such as a protrusion and a groove, atongue and a groove (as illustrated in FIG. 17c), female and malethreads, and the like. In addition, adjoining implants also may becoupled by screws, latches, ratchets, and other conventional couplingarticles. Alternatively, such implants may be coupled by magnetic forcesas well.

[0100] Although auxiliary implants 110, 120, 141-146 may have generalshapes or sizes similar or symmetrical to one other, the detailedgeometry and/or properties thereof may be different. For example,auxiliary implants 110, 120, 141-146 may have the substantiallyidentical shape and size but their treatment layers may have differentcontours to satisfy asymmetrical anatomical contours of the articularsurface to be treated. When symmetric auxiliary implants 110, 120,141-146 include magnetic arrays, they are preferably arranged togenerate specific magnetic fields to meet range of motion of the jointbones. (See the copending '356 application, which is incorporated byreference).

[0101] Depending on the application, the type of implant and location,an intramedullary stem may be desirable to assist in stabilizing theimplant. In the exemplary embodiment for the shoulder described herein,the humeral canal is reamed to the appropriate dimensions and shapeusing a specially adapted standard reamer with a flexible shaft. Withthe canal properly prepared, a modular stem may be inserted as shown inFIGS. 18 and 19. Modular stem 150 preferably is made up of a pluralityof identical stem components 152 including initial and terminalcomponents which may be constructed differently from the rest thereof.The stem components are inserted through an opening in the back side ofcore implant module 130 and dropped into the prepared canal throughoptional opening 154 or they can be placed prior to placing theimplants. A connection means provided on the individual componentscauses them to lock together. For example, as shown in FIGS. 18 and 19,each stem component may be provided with tapered nose 155 and taperedopen tail 156. The tapered nose and open tail are designed such that thenose is received in the tail with a slight interference fit. Stemcomponents 152 also may be provided with internal magnets 156 thatcreate a strong attractive force between the components and effectivelylock them together. Magnets suitable for this purpose are described ingreater detail in the co-pending '356 application, which is incorporatedby reference. Other means for securing the stem components togetherinclude mechanical couplings such as screws or threaded stem components,tongue and groove, and keyed connections and the like.

[0102] As shown in FIG. 19 (shown with a portion of the wall ofcomponent 130 removed), once stem 150 is completely assembled, and aftera further radiographic check to confirm positioning, the core that wasremoved from transversed bone A is replaced to close the bone hole. Thedrill guide retractor is removed. Standard procedures for closure of thewounds and hemostasis are completed following the completion of theimplanting procedures.

[0103] In a further exemplary embodiment, the method of the presentinvention is utilized to perform a non-anatomical total hip arthroplastyin which the femoral head is resected, the acetabulum prepared and theprosthesis implanted via the transosseous core approach. FIG. 20illustrates schematically femoral and acetabular implants according tothe invention, which have been placed via the transosseous core approachof the invention. In this embodiment, a lateral incision is madecentered over the greater trochanter. Once soft tissue has beendissected down to the bone as previously described in connection withthe shoulder replacement embodiment, appropriately sized core cuttingdevice 30 is inserted through drill guide 22 and a bone core is removed.Because the entire joint is replaced in this procedure, the initial corehole may impinge upon the articular surface. The size of the corethrough the femur is generally larger than the shoulder core andaverages 30 mm in diameter, and typically ranges from 22 mm to 35 mm.After the first core is removed and set aside for later reimplantation,the femoral head is resected and removed though the core hole asdescribed in greater below. Preferably the femoral head is resectedrelatively perpendicularly to the longitudinal axis of the femoral neckat its neck level (approximately 15 mm above the lesser trochanter).Finally, the acetabulum is reamed to a depth and a diameter asappropriate for acetabular prosthesis to be implanted.

[0104] Once the bone has been properly prepared, a total hip replacementprosthesis may be implanted. As illustrated in FIG. 20, total hip jointprosthesis assembly 180 according to one embodiment of the presentinvention includes femoral assembly 181 and acetabular assembly 191.Preferably, base 195 of acetabular assembly 191 (shown also in FIGS. 21and 22) is inserted through drill guide 22. Threads 196 or otherprotrusions may be provided to facilitate securing base 195 to the bone.Additionally, provision may be made for screws, other mechanicalfixation elements, magnets or adhesives as previously described. Concaveacetabular implant modules 192 are inserted and, as best seen in FIG.22, secured on lip 194 of base 195 side by side. Hemispherical cup 193is positioned in front of implant modules 194 and cylindrical protrusion198 is coupled to circular groove 197 of implant modules 192 byinterference or pressure fit, thereby assembling acetabular assembly 191in situ. Other methods of interlocking modules of the assembly can alsobe used. After implanting acetabular assembly 191, components of femoralassembly 181 are inserted in the order of head 183, neck 184, and coreimplant module 182. For ease of implantation, neck 184 and core implantmodule 182 may be made as a unitary article, and head 183 may beattached thereto prior to insertion. The components may be securedtogether by interference fits as is known in the art and additionalmechanical elements such as screws, magnets etc. may be provided forgreater security. A stem is inserted which, in this embodiment, isassembled from stem components 152 that are inserted one by one andassembled in situ to form modular stem assembly 150 as previouslydescribed. If desired, the implant may use magnets as described in thecopending '356 application or may be cemented in place. A portion ofbone core C, removed from the femur at the beginning of the proceduremay be replaced to close the bone core hole.

[0105] In order to resect the femoral head as described above,retractable axial cutting device 160 (FIG. 23) and retractabletransaxial cutting device 170 (FIG. 24) may be employed according to thepresent invention. Retractable axial cutting device 160 includescylindrical body 161 having horizontal slit 162 at its distal end.Circular cutting element 163 is coupled to shaft 164, which is in turnmovably retained inside guide 165. Shaft 164 is arranged to movelaterally along an internal guide (not shown), thereby moving cuttingelement 163 between a retracted position (where entire cutting element163 is retained inside slit 162) and an operating position (where adesirable portion of cutting element 163 protrudes out of slit 162).Although not shown in the figure, a power transmission convertsoscillatory or rotational motion of shaft 164 about a longitudinal axisof axial cutting device 160 into another oscillatory or rotationalmotion of cutting element 163 about an axis perpendicular to thelongitudinal axis. Alternatively, a power conveying belt may be used tooscillate or rotate the cutting element. Transaxial cutting device 170includes cylindrical body 171 forming horizontal slit 172 at its distalend. Circular cutting element 173 is vertically disposed and coupled toshaft 174 movably retained inside guide 175 so as to move cuttingelement 173 between a retracted position (where entire cutting element173 is retained inside slit 172) and an operating position (where adesirable portion of cutting element 173 protrudes out of slit 172).

[0106] To resect the femoral head, retractable transaxial cutting device170 is inserted through drill guide 22 and the previously cut bone corehole with cutting element 173 in the retracted position. Afterpositioning transaxial cutting device 170 in the femoral head portionwithin the core hole, cutting element 173 is engaged and moved to itsoperating position to separate the femoral head portion from the femurby cutting the hollow femoral neck from the inner surface of the femoralneck to the outer surface thereof by rotating cutting element 173 oftransaxial cutting device 170 to make serial cuts. After transacting thefemoral head, cutting element 173 is moved to its retracted position andtransaxial cutting device 170 is pulled back from the first core hole,leaving the cut and detached femoral head in the joint (which istypically too big to be removed through the first core hole).Retractable axial cutting device 160 is then inserted through drillguide 22 and the first core hole with cutting element 163 in theretracted position. After positioning vertical cutting device 160 insidethe transacted femoral head, cutting element 163 is engaged and moved toits operating position to cut the femoral head into multiple smallerportions, e.g., by cutting the femoral head along the longitudinal axisinto multiple sections with areas small enough to be removed through thecore hole. Axial cutting device 160 is then removed and femoral headportions are taken out by graspers, forceps or clamps. Alternatively, itmay be preferable to first use the axial cutting device to make severallongitudinal cuts, followed by the transaxial cutting device.

[0107] The method and apparatus according to the present invention cangenerally be applied to any articular joint having at least two majorbones. Further examples include, but are not limited to the elbow,wrist, phalanx, knee, and ankle. Moreover, the transosseous coreapproach according to the invention may be applied in joints involvingthree or more bones wherein multiple first core or auxiliary holes areprovided in one or more more-accessible bones in order to treat singleor multiple less-accessible bones. For example, the elbow includes twoseparate articulations, the first between the humerus and radius, andthe second between the humerus and ulna. Each of these articulationshave surfaces that are subject to individual treatment, potentiallyrequiring multiple core holes to enter the joint at different angleswith respect to the long axis of an extended elbow joint. Anotherexample is the knee joint, which also include two separatearticulations, the patello-femoral joint and the tibio-femoral joint.The patello-femoral joint consists of one compartment and tibio-femoraljoint consists of two compartments. Each of the compartments hasarticular surfaces that are subject to treatment. Based on the teachingsprovided herein, a person of ordinary skill in the art may devise anappropriate treatment for any appropriate joint utilizing the advantagesof the transosseous core approach and associated instrumentationaccording to the invention.

[0108] In general, the orthopedic surgeon can use the present inventionto treat virtually any joint disorder including the results of trauma,instability, early arthritis, end-stage arthritis, tumors, and/or otheranatomical abnormalities. The present invention can also be used intrauma management for the treatment of fractures, cartilage damage,and/or other structural damage. In particular, the present inventionallows the surgeon to gain access to various joints to repair, replace,treat, manipulate, and/or reinforce the joint structures that have beeninjured, without the necessity of dislocating the joint and frequentlywithout involving soft tissue structures such as the articular capsuleand ligaments. The present invention also permits the surgeon to treatinstability, early arthritis, and end-stage arthritis affecting jointsby inserting implants that act as additional restraints or as newsurfaces for the bones of the joint.

[0109] It is to be understood that, while various embodiments of theinvention have been described in conjunction with the detaileddescription thereof, the foregoing is intended only to illustrate andnot to limit the scope of the present invention, which is defined by thescope of the appended claims. Other equivalent embodiments, aspects,advantages, and modifications are within the scope of the followingclaims.

What is claimed is:
 1. A method for treating a joint, wherein the jointincludes at least one first bone, at least one second adjacent bone andsurrounding anatomical structures, and wherein the first bone has anarticular surface and a first region, the second bone has an articularsurface and a first region, and the second bone articular surfacefunctionally opposes the first bone articular surface, the methodcomprising: positioning the first bone with respect to the second bone;removing a bone core from the first bone along a first axis to provide abone core hole beginning in the first bone first region and approachingthe first bone articular surface without penetrating said articularsurface; performing an intervention through said bone core hole; andreplacing at least portion of said first bone core within said bone corehole.
 2. The method of claim 1, wherein said intervention comprisesimplanting at least one component of a prosthetic device within saidfirst bone core hole
 3. The method of claim 1, further comprising:removing the bone core through the first articular surface; preserving acut-out core portion of the first articular surface; subsequent to saidintervention inserting at least a part of the cut-out core portionthrough the first core hole; and reimplanting the cut-out core portionat the first articular surface.
 4. The method of claim 1, furthercomprising an additional step of removing the bone core through saidfirst bone articular surface and into said second bone, said core holeterminating within said second bone.
 5. The method of claim 4, furthercomprising: preserving a cut-out core portion of the second articularsurface; inserting at least a part of the cut-out core portion throughthe first core hole after said intervention; and reimplanting thecut-out core portion at the second articular surface.
 6. The method ofclaim 4, wherein said intervention comprises placing at least onecomponent of a prosthetic implant in the second bone though said firstbone core hole.
 7. The method of claim 4, wherein said interventioncomprises treating intra-joint soft tissue structures through said bonecore hole.
 8. The method of claim 1, wherein said removing bonecomprises: positioning a guide assembly in the first region of the firstbone; inserting a cutting element through the guide assembly; andengaging the cutting element to cut the first core hole in the firstbone.
 9. The method of claim 6, wherein said positioning comprises:inserting a guide wire into the first bone, entering from the firstregion of the first bone and approaching the first articular surface ofthe first bone; and movably positioning at least one of the guideassembly and cutting element over the guide wire.
 10. The method ofclaim 1, further comprising cutting away bone material in at least oneof said bones in a direction away from the first axis and removing saidcut away bone material through said bone core hole in said first bone toprovide a cavity of larger dimension than the core hole.
 11. The methodof claim 10, wherein said cutting comprises removing an end portion ofat least one of said bones.
 12. The method of claim 11, furthercomprising replacing said bone end portion with a first prostheticimplant inserted through said bone core hole.
 13. The method of claim12, wherein said step of removing a bone core further comprises removingthe bone core through said first bone articular surface and into saidsecond bone, and said method further comprises placing a secondprosthetic implant in the second bone though said first bone core hole,said first and second prosthetic implants cooperating to facilitatejoint function.
 14. The method of claim 1, wherein said first region isa non-articular bone surface.
 15. The method of claim 1, wherein saidfirst region is an articular bone surface.
 16. The method of claim 2,wherein said prosthetic device comprises at least two components andsaid components are assembled within the bone core hole.
 17. The methodof claim 2, wherein said prosthetic device includes at least one of: amagnetic array; an implant capable of providing mechanical support tothe bone; and an agent delivery system capable of delivering at leastone agent for treating at least one of the first bone, the second bone,and the surrounding anatomical structures of the joint.
 18. The methodof claim 17 wherein the agent is a pharmaceutical agent capable ofinducing pharmacological intervention in at least one of the bones andthe joint.
 19. The method of claim 18, wherein the pharmacological agentis at least one of steroids, antibiotics and chemotherapeutics.
 20. Themethod of claim 17, wherein the agent is a fluid agent capable ofproviding rheological intervention to the first bone, the second bone,and the surrounding anatomical structures of the joint.
 21. The methodof claim 1 further comprising: cutting the first bone starting from asecond region of the first bone; and ceasing cutting after reaching adepth without cutting the first articular surface, thereby providing thefirst bone with an elongated first auxiliary hole configured to receivean implant.
 22. The method of claim 21, wherein the second region is anarticular bone surface or a non-articular bone surface.
 23. The methodof claim 22, further comprising: inserting at least one first auxiliaryimplant through the first auxiliary hole; and securing the firstauxiliary implant to the first auxiliary hole.
 24. A method for treatinga joint, said joint including at least one first bone, at least onesecond adjacent bone and surrounding anatomical structures, wherein thefirst bone has an articular surface and a first region, the second bonehas an articular surface and a first region, and the second bonearticular surface functionally opposes the first bone articular surface,the method comprising: positioning the first bone with respect to thesecond bone; cutting a hole in the first bone along a first axisbeginning in the first bone first region and passing through the firstbone articular surface; continuing cutting said hole through the secondbone articular surface and into said second bone; terminating cutting ofsaid hole within the second bone; and implanting at least one componentof a prosthetic device within the second bone hole by passing said atleast one component through said first bone hole.
 25. The method ofclaim 24, further comprising cutting away bone material in at least oneof said bones in a direction away from the first axis and removing saidcut away bone material through said hole in said first bone to provide acavity of larger dimension than the hole.
 26. The method of claim 24,wherein: said prosthetic device comprises multiple components; and saidimplanting comprises assembling said multiple components together toform the prosthetic device within the bone hole.
 27. The method of claim24, wherein said cutting comprises coring the bone to provide a bonecore suitable for at least partial replacement.
 28. The method of claim24, further comprising: changing the position of the first bone withrespect to the second bone; cutting out a second portion of the secondarticular surface through the first bone hole; cutting a second hole inthe second bone and into an interior thereof through the first bonehole; and ceasing cutting after reaching a predetermined depth, therebyproviding the second bone with a second hole.
 29. A method for treatinga joint, said joint including at least one first bone, at least onesecond adjacent bone and surrounding anatomical structures, wherein thefirst bone has an articular surface and a first region, the second bonehas an articular surface and a first region, the method comprising:positioning the first bone with respect to the second bone; cutting ahole having a first diameter in the first bone along a first axisbeginning in the first bone first region and passing through the firstbone articular surface; continuing cutting said hole through the secondbone articular surface and into said second bone; enlarging said hole toa second diameter greater than the first diameter at a location spacedaway from the first bone first region; and implanting at least onecomponent of a prosthetic device within the enlarged hole by passingsaid at least one component through said hole with the first diameter.30. The method according to claim 29, wherein said prosthetic devicecomprises plural implant modules, said modules being sized to be passedthrough said first diameter bone hole, said method further comprising:inserting each module individually through said first diameter bonehole; and assembling the prosthetic device implant modules within thesecond diameter bone hole.
 31. The method according to claim 30,wherein: said enlarging comprises resecting a terminal end portion of atleast one bone, including the associated articular surface and removingresected materials through the first diameter bone hole; and saidprosthetic device comprises a total joint prosthesis.
 32. The methodaccording to claim 30, wherein at least one of said bones includes anintramedullary canal and said method further comprises: inserting a toolthrough said first diameter bone hole and into the intramedullary canal;preparing the intramedullary canal with said tool; inserting segments ofan intramedullary rod into said canal through the first diameter bonehole; and assembling said intramedullary rod in the intramedullarycanal.
 33. The method according to claim 30, wherein the joint is ashoulder and the prosthetic device comprises a humeral component and aglenoid component.
 34. The method according to claim 33, wherein eachsaid component comprises plural implant modules, said method furthercomprising inserting, assembling and implanting said glenoid componentmodules followed by inserting, assembling and implanting said humeralcomponent modules.
 35. The method according to claim 30, wherein thejoint is a hip and the prosthetic device comprises a femoral componentand an acetabular component.
 36. The method according to claim 35,wherein each said component comprises plural implant modules, saidmethod further comprising inserting, assembling and implanting saidacetabular component followed by inserting, assembling and implantingsaid femoral component.
 37. A surgical kit, comprising: a bone cuttingtool having a cutting element for creating a bone hole of a firstdiameter; and a bone prosthesis assembly comprising at least two implantmodules configured and dimensioned to be separately inserted through thebone hole of the first diameter and to mate together at a site ofinterest to form said assembly.
 38. The surgical kit according to claim37, further comprising a surgical hemostat for treating the wall of thebone hole, said hemostat comprising: an applicator expandable from aretracted position to a expanded position; a cylindrical, expandablesleeve configured and dimensioned to be disposed over said applicator inthe retracted position; and a hemostatic agent disposed on said sleeve,wherein expansion of said applicator to the expanded position within abone hole forces said hemostatic agent against the wall.
 39. Thesurgical kit according to claim 38, wherein said hemostat applicatorcomprises: a central member; a plurality of extendable arms disposedradially around said central member plural platen portions, each mountedon at least one said arm, said platen portions together defining an atleast substantially cylindrical surface around the central member sizedto receive said sleeve; and an expansion mechanism operatively connectedto said arms such that actuation of the expansion mechanism extends saidarms thereby moving the applicator from the retracted position to theexpanded position.
 40. The surgical kit according to claim 37, whereinsaid bone prosthesis assembly includes a replacement articular surface,said surface being comprised of plural implant modules capable of beinglocked together to form at least a portion of a uniform articularsurface.
 41. The surgical kit according to claim 40, wherein saidprosthesis assembly is augmented with at least one magnet.
 42. Thesurgical kit according to claim 37, further comprising a cartilage punchhaving an operative portion configured and dimensioned to be insertedthrough said first diameter bone hole and manipulated from outside saidhole, said operative portion including a blade surrounding a centralcavity to capture cartilage cut by said blade.
 43. The surgical kitaccording to claim 37, further comprising at least a second bone cuttingtool with an operative portion configured and dimensioned to be insertedthrough said first diameter bone hole and manipulated from outside saidhole, said operative portion including at least one cutting member forremoving bone material to provide a larger void within said firstdiameter bone hole.
 44. The surgical kit according to claim 43, whereinsaid second bone cutting tool comprises: an elongated body having alongitudinal axis and defining an opening in a distal portion thereof;and a cutting member movably disposed within said body, said cuttingmember movable between a first position disposed within said body and asecond position extending out of said opening for cutting bone.
 45. Thesurgical kit according to claim 43, wherein said second bone cuttingtool comprises: a central member; a plurality of arms extending radiallyfrom the central member, said arms being extensible in the radialdirection between retracted and expanded positions; a bone reamingmember disposed on each said arm opposite the central member; anexpansion mechanism operatively connected to said plurality arms suchthat the distance of said bone reaming members from said central membermay be controlled from outside the first diameter bone hole.
 46. Thesurgical kit according to claim 45, wherein said second bone cuttingtool arms are telescoping and said reaming members have an outer surfacewith a radius of curvature approximately equal to a radius of a space tobe reamed in its expanded position and have a diameter less than thefirst core hole to allow passage thereof through the hole in itsretracted position.
 47. The surgical kit according to claim 43, whereinsaid kit is adapted for joint replacement and wherein said boneprosthesis assembly comprises first and second components correspondingto first and second articular surfaces of the joint and each saidcompetent is comprised of plural implant modules configured anddimensioned to be inserted through said first diameter bone hole andassembled within said larger void.
 48. The surgical kit according toclaim 47, wherein said kit is adapted to replace at least a portion of ashoulder joint and said bone prosthesis assembly comprises at least oneof: a glenoid component comprised of implant modules configured anddimensioned to be inserted through the first diameter bone hole in thehumerus and assembled for implantation in the scapula; and a humeralcomponent comprised of implant modules configured and dimensioned to beinserted through said bone hole in the humerus and assembled forimplantation in the humerus replacing at least a portion of the humeralhead and cooperating with at least one of said glenoid component andanatomical glenoid.
 49. The surgical kit according to claim 47, whereinsaid kit is adapted to replace at least a portion of a hip joint andsaid bone prosthesis assembly comprises at least one of: an acetabularcomponent comprised of implant modules configured and dimension to beinserted through the first diameter bone hole in the femur and assembledfor implantation in the iliac bone; and a femoral component comprised ofimplant modules configured and dimensioned to be inserted through saidbone hole in the femur and assembled for implantation in the femurreplacing at least a portion of the femoral head and cooperating with atleast one of said acetabular component and anatomical acetabulum.
 50. Aprosthetic assembly adapted to be inserted through a bone hole having afirst hole diameter and implanted at a site of interest within a bone orjoint, said assembly when assembled having at least one dimension largerthat the first hole diameter, wherein: said assembly comprises at leasttwo implant modules configured and dimensioned to be individuallyinserted through said bone hole; and said implant modules fit togetherat the site of interest to form said prosthetic assembly.
 51. Theprosthetic assembly according to claim 50, wherein said assemblyincludes a replacement articular surface, said surface being comprisedof plural implant modules capable of being locked together to form atleast a portion of a uniform articular surface.
 52. The prostheticassembly according to claim 51, wherein said assembly is augmented withat least one magnet.
 53. The prosthetic assembly according to claim 52,wherein said articular surface is formed with a magnetic array.
 54. Theprosthetic assembly according to claim 51, wherein said implant modulesinclude at least one core module configured and dimensioned with saidfirst hole diameter to closely match said bone hole and at least oneauxiliary module configured and dimensioned to couple with said coremodule and extend outwardly therefrom.
 55. The prosthetic assemblyaccording to claim 51, wherein: the site of interest is a joint; saidassembly includes at least one of a first and second componentscorresponding to at least a portion of the first and second articularsurfaces of the joint; each said competent is comprised of pluralimplant modules configured and dimensioned to be inserted through saidbone hole.
 56. The prosthetic assembly according to claim 55, whereinthe joint is a shoulder and said assembly comprises at least one of: aglenoid component comprised of implant modules configured anddimensioned to be inserted through said first diameter bone hole in thehumerus and assembled for implantation in the scapula; and a humeralcomponent comprised of implant modules configured and dimensioned to beinserted through said first diameter bone hole in the humerus andassembled for implantation in the humerus replacing at least a portionof the humeral head and cooperating with at least one of said glenoidcomponent and anatomical glenoid.
 57. The prosthetic assembly accordingto claim 55, wherein the joint is a hip and said assembly comprises atleast one of: an acetabular component comprised of implant modulesconfigured and dimension to be inserted through said first diameter bonehole in the femur and assembled for implantation in the iliac bone; anda femoral component comprised of implant modules configured anddimensioned to be inserted through said first diameter bone hole in thefemur and assembled for implantation in the femur replacing at least aportion of the femoral head and cooperating with at least one of saidacetabular component and anatomical acetabulum.
 58. A surgical tool forcutting bone, comprising: an elongated body having a longitudinal axisand defining an opening in a distal portion thereof; and a cuttingmember movably disposed within said body, said cutting member movablebetween a first position disposed within said body and a second positionextending out of said opening for cutting bone.
 59. The tool accordingto claim 58, further comprising: a guide disposed inside the body; and ashaft movably disposed inside the guide and configured to move between aretracted position and an operating position substantially along theradial axis of the body, with said cutting member is operably disposedon said shaft; wherein said cutting member has a periphery with teeththere around and said member is configured to move with the shaftbetween the retracted and operating positions, and the teeth areconfigured to be retained inside the body in its retracted position andat least some of the teeth protrude outside the body through the openingof the body.
 60. The surgical tool of claim 58, wherein the cuttingmember is a circular blade and said shaft is disposed transverse to thelongitudinal axis with said body opening of extending substantiallyalong the longitudinal axis of the body to permit cutting an object in adirection substantially parallel with the longitudinal axis of the body.61. The tool according to claim 58, wherein the cutting member is acircular blade and said shaft is disposed parallel to the longitudinalaxis with said body opening extending substantially transverse to thelongitudinal axis of the body to permit cutting an object in a directionsubstantially perpendicular to the longitudinal axis of the body.
 62. Asurgical hemostat for treating walls of bone holes, comprising: anapplicator expandable from a retracted position to a expanded position;and a cylindrical, expandable sleeve configured and dimensioned to bedisposed over said applicator in the retracted position; and ahemostatic agent disposed on an outer surface of said sleeve, whereinexpansion of said applicator to the expanded position within a bone holeforces said hemostatic agent against the bone hole wall.
 63. Thesurgical hemostat according to claim 62, wherein said applicatorcomprises: a central member; a plurality of extendable arms disposedradially around said central member plural platen portions, each mountedon at least one said arm, said platen portions together defining an atleast substantially cylindrical surface around the central member; andan expansion mechanism operatively connected to said arms such thatactuation of the expansion mechanism extends said arms thereby movingthe applicator from the retracted position to the expanded position. 64.A surgical hemostat for treating the walls of bone holes, comprising: acylindrical, expandable sleeve configured and dimensioned to be disposedover an expandible applicator; and a hemostatic agent disposed on saidsleeve, wherein expansion of the expandable applicator within a bonehole forces said hemostatic agent against the wall and retraction of theapplicator permits its removal while leaving at least a portion of saidsleeve and agent within the hole.
 65. An expandable surgical bonereamer, comprising: a central member; a plurality of arms extendingradially from the central member, said arms being extensible in theradial direction between retracted and expanded positions; a bonereaming member disposed on each said arm opposite the central member; anexpansion mechanism operatively connected to said plurality arms suchthat the distance of said bone reaming members from said central membermay be controlled.
 66. The bone reamer according to claim 65, whereinsaid arms are telescoping and said reaming members have an outer surfacewith a radius of curvature approximately equal to a radius of said bonereamer with said arms in the retracted position.